The present invention is a cryptographic key management system that uses pre-positioned key splits to build cryptographic keys when needed. This paper describes an architecture that provides a complete cryptosystem for today's large distributed networks. The management system of the present invention will be referred to herein as “CKM”.
Keys are an essential part of all encryption schemes. Their management is a critical element of any cryptographic-based security. The true effectiveness of key management is the ability to have keys created, distributed, and maintained without requiring user interaction and without penalizing system performance or costs.
As symmetric, also called public-key, cryptography has received significant attention in recent years. The public-key method includes separate public encryption and private decryption keys that provide a measure of difficulty in deriving the private key from the public key. Public-key management was developed to establish cryptographic connectivity between two points in a communications channel after which a symmetric cryptogen, such as DES (Data Encryption Standard), was to be executed. Over the years public-key implementations have demonstrated their effectiveness to authenticate between entities. However, public-key methods have not been able to successfully handle the requirements of today's global networks.
Many of the recent public-key implementations allow users to create their own keys. This can leave an organization vulnerable, and in some cases liable, if users leave and fail to identify their private keys. Also, to ensure the integrity of public keys, third party infrastructure designs have been proposed. A Certificate Authority process confirms that a certain public key was issued to a specific user. The exchange of certificates with a third party can significantly impact the performance of a network.
The public-key process is also associated with high computation times. In many instances, hardware solutions have compensated for these high computational requirements. Since public-key architectures have been historically point-to-point designs, moving to a distributed network with group sharing of information can create higher transmission costs and greater network impact. While public-key management systems work well for point-to-point communications and one-to-one information transfer, they are too time consuming for a single file placed on a server and decrypted by thousands of users. As the trend toward work groups and complex communications infrastructures continues, the need for a more efficient information and communications key management technology becomes paramount.
Shared secret keys used with symmetric key cryptosystems is the earliest key management design and pre-dates public-key management. Early symmetric key designs suffered from the “n-squared” problem since the number of keys required becomes very large and unmanageable as the number of users increase. In addition, these designs did not have effective authentication. Symmetric encryption does have significantly better processing performance than public-key implementations.
CKM builds on the advantages, and takes into account the disadvantages, of both public-key and symmetric key implementations. CKM combines an encryption process based on split key capability with access control credentials and an authentication process based on public-key techniques. CKM is most effective in modern distributive information models where information flow and control can be defined, where the information encrypted may need to be recovered, and where authentication using public-key technology and a physical token can be implemented.
This paper emphasizes the encryption of data-at-rest as opposed to data-in-transit. Data-at-rest refers to data encrypted as logical units (objects) and includes the creation, processing, transfer, and storage of these objects. Data-in-transit refers to the stream encryption of data moving through a physical or logical communication channel during a certain period of time. CKM can perform both types of encryption. The data-in-transit capability will be emphasized in a future release of this paper.